A Chiari malformation (CM) is a type of structural change that affects the lower part of the brain. It’s most often due to a congenital condition that affects the shape or size of the skull.

Chiari malformation, an anomaly of the posterior cranial fossa, also known as Arnold–Chiari malformation, was described in autopsies by Hans Chiari, an Austrian pathologist, in 1891. He defined four ...

Chiari malformation type I (CMI) is a congenital neurological disorder characterized by the herniation of cerebellar tonsils through the foramen magnum, leading to impaired cerebrospinal fluid (CSF) ...

Some CMs are asymptomatic and do not interfere with a person’s activities of daily living. In other cases, medications may ease certain symptoms, such as pain. Surgery is the only treatment available ...

Retrosigmoid craniotomy is a surgical approach that can treat brain tumors, lesions, and other health conditions that affect the posterior fossa, an area at the back of the skull. Approaches like this ...